Dustdying
by MarvelousManiac
Summary: (HALLOWEEN SPECIAL TWO-SHOT!) What if Undyne decided to collect LV to kill Frisk? Dusttale AU
1. Chapter 1

**This was something I came up with when I asked myself, "What if someone instead of Sans or Papyrus went Genocide in Dusttale?". Hope you enjoy.**

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Undyne never thought anything like this would happen. She never thought that someone as lazy as Sans would've done something like this. She never thought she would have to kill a monster. She never would've thought anything like that. But now, Sans went berserk. Now, all the monsters in the underground have to head to safety. Now, she's face-to-face with the skeleton and she has no choice but to protect New Home and kill Sans.

"How could you Sans?" Undyne asked in anger.

Sans stood in front of her with his hood up and with both his eyes glowing red.

"How could you betray us?! What has the underground...what has YOUR BROTHER done to deserve this?!"

Sans just said nothing as he lowered his head.

"ANSWER ME!"

Sans then stood quiet for a moment and said, "i don't expect you to understand what i'm doing. i don't expect you to understand anything. all i'm asking is that you hold still so i can get the job done. the human must be stopped!"

"Human? What human?"

Sans then summoned a bone attack at Undyne. Undyne then dodged Sans' attack and threw a bunch of her magic spears at him. Sans then teleported out of the way of the spears and behind Undyne. He then tried to summon a bunch of bones straight up from the ground to kill Undyne, but Undyne avoided his attack and used her green magic to keep Sans in place as she summoned spears to attack him at all sides.

Sans then started blocking spears with a bone in his hand. The spears then started to go faster as Sans was getting tired. And then Undyne took her chance to strike him down. She charged at him with her spear in hand, released Sans from her green magic, and struck her spear into his chest. Sans' blood (or was it ketchup) poured from where he was struck as his HP was going down.

"I had to do it Sans. As a royal guard, I'll do whatever it takes to protect the monsters of the underground, including my friends."

Sans then looked over at Undyne and muttered his final words. "what do you think i was doing?" Sans then turned to dust as nothing but his coat was left.

"I'm sorry Sans. You left me no choice." Undyne was then about to walk off as she heard a voice.

_"MORRREEEEE!"_

"WHO SAID THAT?! SHOW YOURSELF!"

_"YOOOOUUU NEEEEDDD MORRREEEE!"_

"I-I'm not messing around! COME OUT!"

_"YOU NEED TO KILL MORE MONSTERS! COLLECT MORE LV! GROW MORE STRONGER!"_

"Stop! Please! G-Get out of my head!"

_"KILLLLL! KILLLLL! KIIIIIIIIILLLLL!"_

"AHHHHHHHHHHH!"

* * *

Alphys was locked inside her lab, staring up at her monitor to look through her security cameras to see if she could catch anything. All the cameras from the entrance of the Ruins to Waterfall had been destroyed by Sans. The last thing she caught was Undyne going up to stop Sans from hurting anyone else. Alphys just couldn't believe that Sans would go mad like this.

He would've had no reason to do it. He was living a good life with his brother, he usually never overworked himself, and he sure wasn't made fun of. So why did he do it? That was a question Alphys didn't have time to worry about right now. The thing she needed to find out was whether or not Undyne survived and if she needed to worry about Sans anymore.

So she looked through the camera that was just outside her lab, and she saw Undyne walking up to her front door while drinking water from a cup. At first she was relieved to know she was alright, but then she noticed that the other guards were nowhere to be seen. She could've sworn they were there a second ago. Undyne then started banging on the door as Alphys quickly got up and opened it for her. Undyne then stepped in and fell to the floor on all fours.

"U-Undyne! A-Are you okay?" Alphys asked with concern but Undyne didn't answer. "W-What happened with S-Sans? D-Did you k-kill him?"

Undyne still didn't answer.

"D-Do you still need water? I-I'll get it for you!" Alphys then ran out of her lab and over to the water dispenser. She then filled a cup and ran back to the lab without spilling any water or letting anything evaporate.

But, as she ran back inside, she noticed that Undyne wasn't there in the floor anymore. "U-Undyne? W-Where are you? W-Where did you go?"

A spear then appeared from the ground in front of her. She then looked up to see Undyne up on the second floor, standing on the railing. "U-Undyne?"

Undyne then jumped from the railing and towards Alphys with a spear in hand. Alphys then dodged Undyne and ran for the elevator. Then, suddenly, spears appeared in front of the elevator, blocking Alphys from getting in. Alphys then tried running for the back door as spears appeared there too. Alphys was then trapped inside the lab with Undyne, who was walking towards her ready to kill her.

"U-Undyne! W-What are you doing? I-It's me, A-Alphys!"

Undyne ignored her cries as she kept walking closer. Alphys was then backed into a wall with nowhere to go.

"U-Undyne! P-Please! I-I'm your friend!"

Undyne then hesitated for a moment before saying, "I'm sorry Alphys. But the human has to be stopped."

"Undyne wait!"

Undyne then struck Alphys with her spear as she died and turned to dust. Undyne then got down on her knees and started sobbing. "I'M SORRY ALPHYS! I-I DIDNT MEAN TOO!" Undyne then continued sobbing until she stopped and said, "Wait, why am I sorry? This isn't my fault! It's...It's...IT'S THE HUMAN'S FAULT! IT'S THEIR FAULT I DID THIS! ALL BECAUSE OF THEIR STUPID RESETS! AND THEIR STUPID BLOODLUST! BECAUSE THEY'VE BEEN DOING ALL OF THIS OVER AND OVER AGAIN! Well, that's no longer gonna happen! BECAUSE I WILL KILL EVERY MONSTER LEFT! I WILL GAIN MORE LV THEN THEY HAVE! AND THEN...I will end them. HAHAHAHAHAHAHAHAAHAHAHAHAHAHAHAHA!"

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**So, what do you think so far? Leave your thoughts in a review below! And I'll see you next chapter!**


	2. Chapter 2

Undyne then left the lab and arrived at Muffet's web, where she was met by the mother of all spiders herself. As expected, Muffet didn't know what Undyne came there to do, until she summoned a spear and killed her on the spot. She then continued to kill off every spider there. She then decided to head off until she heard a voice say, _"That idiot should've evacuated like I told her too."_

The voice wasn't the same one as before, instead it sounded...familiar to Undyne. She then turned around and asked, "Who's there?"

She then heard the voice say, _"You know who I am, Undyne. How could you forget me? I mean, after all, we were great friends. "_

Undyne then saw someone appear in front of her. They appeared to be have no torso, legs, not arms, leaving only a head and both hands. The head and claws belonged to that of a certain yellow reptilian. Undyne could recognize her anywhere, there no mistake about it.

"Alphys? I-I thought I..."

_"Killed me? You did. And I died. But I never left you."_

The voice of Alphys' spirit sounded a little more twisted, but it her voice nonetheless.

_"neither did i." _Another twisted voice said.

Undyne then turned to see the spirit of the comedic skeleton.

"Sans?"

_"you remember them don't you?"_

"Remember what?"

_"THE RESETS." _Yet another voice chimed in. And this one belonged to...

"Papyrus? What is going on?"

_"WELL? DO YOU REMEMBER?"_

Undyne stayed silent for a moment before saying, "Yes."

_"Every reset?" _Alphys questioned.

"Yes."

_"every genocide run?" _Sans questioned.

"Yes!"

_"EVERY TIME THE HUMAN SLAUGHTERED YOU IN COLD BLOOD AND TOOK YOUR EXP?"_ Papyrus asks.

"YES!"

_"Then you know what you must do!" _Alphys exclaimed. _"You must kill every monster!"_

_"take their exp!" _

_"LEVEL UP YOUR LV AND...?"_

"KILL THE HUMAN!"

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Frisk then arrived at the famous MTT Resort, Hotland's biggest apartment-building turned hotel. Frisk saw the red arrow on the floor next to the building, leading to an alleyway. They thought about heading that way until Chara said, _**"**__**Don't bother. We BOTH know they're not there."**_

Frisk then walks into the hotel to see a leaking fountain where the Mettaton statue used to be. They then noticed that Burgerpants was no longer behind the counter to sell Mettaton-themed food. Frisk then decided to head into the diner to see if anyone was in there. Then, right as they were about to pass the table where he Sans would've sat, the lights turned off. It was completely pitch black before the lights turned back on for Frisk to see, to their surprise, Undyne sitting where Sans used to sit whenever he and Frisk were here.

Undyne looked a little different than she used to though. Her eye was emitting a red color and her face and armor bared scars as if she had returned from battle. Undyne then gave Frisk a toothy, sinister grin and said, "You remember this place, don't you punk?"

Frisk didn't answer.

"You remember when Sans took you to this exact table and told you about how he made a promise to a 'lady behind the door' to watch over you and to make sure no harm would come to you. He also said that if he didn't make that promise, that you'd be dead where you stood. Of course, he passed it off as some sort of twisted joke, but...he was **dead** serious."

Frisk couldn't tell if she was emphasizing the word "dead" or making a pun, but they cringed either way.

"Tell me, do you ever miss those times? Because, let me tell you punk...Sans certainly doesn't." Undyne then stretched her grin into a twisted smile as the lights turned off and back on again and she disappeared.

Frisk just stood there in utter shock at what they just witnessed. Apparently, Sans is long gone and now Undyne has gone mad with a lust for LV. This must also mean that Undyne has the exact abilities of her and Sans' victims.

Chara then interrupted Frisk's thoughts by saying, **"Don't just stand there, get a move on before she steals our LV!"**

Frisk then ran out of the diner, and straight to the core.

* * *

Frisk then showed up at Judgement Hall, the very hall where Sans would appear to judge and execute them for their every action. Only this time, as they were walking down the hall, Undyne appeared. The bells then rung throughout the hall, echoing off the walls and into the ears of the human and the monster.

"Well then, here we are." Undyne said. "At the end of the line. Judgement Hall. The very place where Sans would be the judge, jury, and executioner of you. Only this time, I'm here, and I have more LV then you do. I'm more determined then you'll ever be! And now, as Sans would've said, you and I are gonna have a BAD TIME!"

Undyne then summoned a spear in her hand and stood in a fighting stance. "So what do you say, punk?"

Frisk then drew out their knife and began to charge at Undyne. Undyne then started charging back as she yelled her battle cry.

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**Happy Halloween! Puny Mortals! Muhahahaha!**


End file.
